Shower Drain for Oval Hole
When my shower drain cover broke, rather than destroying the ceiling below, I used plumbers epoxy to build it back up. It works fine, but the hole was a bit irregular. I designed this cover to fit into the oddly shaped hole, and provide good drainage, while being safe to stand on. If it looks interesting remember that it will need to be customized for your particular situation.
Also recommended - http://www.thingiverse.com/thing:1115235